1. Field of the Invention
The present invention relates to a method for accessing a portion of the data stored on a microprocessor card and, more particularly, to a method for accessing data stored on Subscriber Identity Module (SIM) cards for mobile phones having a microprocessor and at least one accessible card number.
2. Description of the Related Art
European Patent No. EP 0 607 767 A1 discloses a SIM card that contains a Personal Identity Number (PIN) code that the subscriber must enter to gain access to the mobile phone network. The SIM card checks the PIN entered by the user to determine whether access is authorized; if access is authorized, the mobile phone gains access to special data on the SIM card, with which the mobile phone announces the subscriber to the network operator. This ensures that only authorized persons, i.e. only those having access to or knowing the PIN, can make calls using the SIM card.
In addition, another code, known as the International Mobile Subscriber Identity (IMSI) code, is also stored on the SIM card. European Patent No. EP 0 607 767 A1 further discloses the assignment or personalization of a mobile telephone to a SIM card by means of comparison with the IMSI code. A list of IMSI codes stored in the mobile phone is compared with the IMSI code on the SIM card; only when the codes agree will the mobile phone be activated.
Until now, access to the information stored on SIM cards has been restricted to the issuer of the cards, i.e. the cellular phone company. There is however an unmet need for a method that allows access to at least a portion of the data stored on the SIM card for specific and limited purposes, e.g. by sales and service persons for configuration and quality control.